How many millimeters is a standard trading card
A standard modern trading card measures 63.5 mm by 88.9 mm. That size is the common, portrait-format dimension used for most trading cards from sports sets like baseball, basketball, football, hockey and soccer, and it matters to collectors for storage, grading and scanning.
Quick facts
- Standard size
- 63.5 mm by 88.9 mm
- Orientation
- portrait
Quick answer
Standard trading cards measure 63.5 mm by 88.9 mm. The first figure (63.5 mm) is the short side and the second (88.9 mm) is the long side, so the card is in portrait orientation.
Where that size comes from
Manufacturers settled on this size to fit common protective sleeves, binders and retail packaging. The dimensions are also compatible with many card scanners and camera setups used to capture trading card images and identifier details for inventories.
Why it matters to collectors and grading services
Collectors and grading services such as PSA expect standard cards to be near 63.5 mm by 88.9 mm when authenticating and assigning a grade. Small deviations can affect centering evaluations and how a card sits in a holder, so knowing the standard size helps when comparing cards and submitting them for grading.
How to measure your cards
Use a metric ruler or calipers and measure edge-to-edge without including top loaders or sleeves. Measure the short side first and the long side second; you should read roughly 63.5 mm by 88.9 mm for a standard card. Keep the card flat and steady to get an accurate millimeter reading.
Using the measurement with tools and apps
When you scan or photograph cards for inventory or sale, include the measurement 63.5 mm by 88.9 mm in your notes and tag the item as a standard portrait card. Slabbr can help organize scans and identifiers alongside size, grade and other collector details.
Common questions
- Are all sports cards the same size?
- Most modern baseball, basketball, football, hockey and soccer cards follow the 63.5 mm by 88.9 mm standard, but variations exist. Promo cards, inserts, oversized cards and mini cards can differ in dimensions.
- What if my card doesn't measure exactly 63.5 mm by 88.9 mm?
- Minor manufacturing tolerances are normal. Small differences of a millimeter or two do not automatically indicate a counterfeit, but larger discrepancies or odd proportions can be a sign the card is non-standard. For grading, exact centering and edge measurements factor into the assigned grade.